My motor went dead after a while, so I posted a topic to this forum. MBDOC told me to check the ignition switch, and when I took it off, sure enough, it was the culprit. It makes sense that after a million turns, the contacts on those switches wear out. Well, I've replaced it and my motor is blowing fine again. Maybe you should look at that.
91 Supercharged Miata
99 E320 Wagon